Block B1 is a locality within Janakpuri, West Delhi, Delhi. Block B1 has a pincode of . Nearby localities of Block B1 include Block B1, Nangli Jalib, Janakpuri District Center, BB Block, Possangipur, Chhoti Subji Mandi, Prem Nagar, Shiv Nagar, Narang Colony, Chander Nagar, Gurunanak Pura, Virender Nagar, Shiv Nagar Extension, Block C2A, Block A3, Block C2B, Hari Nagar, C-2 Block, Asalatpur Village, Block C2C, Block C1, Block C 4E, Block C4F, Block A1, Block A2, Block C4G, Block C4H, Block C 2D, Block C3A, Block C3, RWA Colony, Tihar Jail, Tihar Central Jail, Desu Colony, Janakpuri Institutional Area, Lajwanti Garden, Pocket D 1, Nangal Raya